In recent years, light emitting devices such as a red LED have a widely enhanced luminance, with an increased frequency of use, as a light source for traffic sign indicators, signals, indication displays, or the like.
Moreover, in recent years, there have been proposals to provide such light emitting devices with another function than indication, such as a function for communications, for a multi-functionality to be implemented.
For instance, in Japanese Patent Application Laid-Open Publication No. 2002-202741, there is a disclosure of techniques for a light emitting device in use as a traffic sign indicator to be flashed on and off to transmit information, such as phonetic information, to running vehicles. Further, in Japanese Patent Application Laid-Open Publication No. 2004-185359, there is a disclosure of techniques for a light emitting device in use as illumination to be flashed on and off to transmit phonetic information, such as a guiding message.